The present invention generally relates to dielectric chips and more specifically to the fabrication of tunable dielectric chips. Still more particularly the present invention relates to the fabrication of tunable dielectric chips that are made from Paracan tunable dielectrics.
RF microwave devices made of tunable dielectrics (such as Parascan, the trademarked tunable dielectric material invented by Paratek Microwave Corporation, the assignee of the present invention) is typically screen printed on different gsubstrates to form a thick film layer. These dielectric films have average surface roughness between 0.4 um to 1 um and peak to valley roughness more than 4 um. A thin film layer more than 3 um is required to pattern on these rough thick films in order to make tunable RF devices. Typically, in the semiconductor industry, thin film is patterned on a smooth surface such as a polished silicon wafer and the thickness of the film is less than 1 um. Patterning a 3 um or thicker thin film on rough dielectrics is a challenge.
Therefore, a strong need in the industry exists to provide the ability to pattern a 3 um or thicker thin film on rough dielectrics to enable the fabrication of tunable dielectric chips that are made from Paracan tunable dielectrics.